Magnetic tunnel junctions, methods used while forming magnetic tunnel junctions, and methods of forming magnetic tunnel junctions

ABSTRACT

A method used while forming a magnetic tunnel junction comprises forming non-magnetic tunnel insulator material over magnetic electrode material. The tunnel insulator material comprises MgO and the magnetic electrode material comprises Co and Fe. B is proximate opposing facing surfaces of the tunnel insulator material and the magnetic electrode material. B-absorbing material is formed over a sidewall of at least one of the magnetic electrode material and the tunnel insulator material. B is absorbed from proximate the opposing facing surfaces laterally into the B-absorbing material. Other embodiments are disclosed, including magnetic tunnel junctions independent of method of manufacture.

RELATED PATENT DATA

This patent resulted from a divisional application of U.S. patentapplication Ser. No. 14/684,110, filed Apr. 10, 2015, entitled “MagneticTunnel Junctions, Methods Used While Forming Magnetic Tunnel Junctions,And Methods Of Forming Magnetic Tunnel Junctions”, naming Gurtej S.Sandhu as inventor, the disclosure of which is incorporated byreference.

TECHNICAL FIELD

Embodiments disclosed herein pertain to magnetic tunnel junctions, tomethods used while forming magnetic tunnel junctions, and to methods offorming magnetic tunnel junctions.

BACKGROUND

A magnetic tunnel junction is an integrated circuit component having twoconductive magnetic electrodes separated by a thin non-magnetic tunnelinsulator material (e.g., dielectric material). The insulator materialis sufficiently thin such that electrons can tunnel from one magneticelectrode to the other through the insulator material under appropriateconditions. At least one of the magnetic electrodes can have its overallmagnetization direction switched between two states at a normaloperating write or erase current/voltage, and is commonly referred to asthe “free” or “recording” electrode. The other magnetic electrode iscommonly referred to as the “reference”, “fixed”, or “pinned” electrode,and whose overall magnetization direction will not switch uponapplication of the normal operating write or erase current/voltage. Thereference electrode and the recording electrode are electrically coupledto respective conductive nodes. The resistance of current flow betweenthose two nodes through the reference electrode, insulator material, andthe recording electrode is dependent upon the overall magnetizationdirection of the recording electrode relative to that of the referenceelectrode. Accordingly, a magnetic tunnel junction can be programmedinto one of at least two states, and those states can be sensed bymeasuring current flow through the magnetic tunnel junction. Sincemagnetic tunnel junctions can be “programmed” between twocurrent-conducting states, they have been proposed for use in memoryintegrated circuitry. Additionally, magnetic tunnel junctions may beused in logic or other circuitry apart from or in addition to memory.

The overall magnetization direction of the recording electrode can beswitched by a current-induced external magnetic field or by using aspin-polarized current to result in a spin-transfer torque (STT) effect.Charge carriers (such as electrons) have a property known as “spin”which is a small quantity of angular momentum intrinsic to the carrier.An electric current is generally unpolarized (having about 50% “spin-up”and about 50% “spin-down” electrons). A spin-polarized current is onewith significantly more electrons of either spin. By passing a currentthrough certain magnetic material (sometimes also referred to aspolarizer material), one can produce a spin-polarized current. If aspin-polarized current is directed into a magnetic material, spinangular momentum can be transferred to that material, thereby affectingits magnetization orientation. This can be used to excite oscillationsor even flip (i.e., switch) the orientation/domain direction of themagnetic material if the spin-polarized current is of sufficientmagnitude.

An alloy or other mixture of Co and Fe is one common material proposedfor use as a polarizer material and/or as at least part of the magneticrecording material of a recording electrode in a magnetic tunneljunction. A more specific example is Co_(x)Fe_(y)B_(z) where x and y areeach 10-80 and z is 0-50, and may be abbreviated as CoFe or CoFeB. MgOis an ideal material for the non-magnetic tunnel insulator. Ideally suchmaterials are each crystalline having a body-centered-cubic (bcc) 001lattice. Such materials may be deposited using any suitable technique,for example by physical vapor deposition. One technique usable toultimately produce the bcc 001 lattice in such materials includesinitially forming CoFe to be amorphous and upon which MgO-comprisingtunnel insulator material is deposited. During and/or after thedepositing, the MgO tunnel insulator, the CoFe, and the tunnel insulatorideally individually achieve a uniform bcc 001 lattice structure.

Boron is commonly deposited as part of the CoFe to assure or provideinitial amorphous deposition of the CoFe. Crystallization of the CoFecan occur during or after deposition of the MgO by annealing thesubstrate at a temperature of at least about 350° C. This will inducethe diffusion of B atoms out of the CoFe matrix being formed to allowcrystallization into bcc 001 CoFe. Bcc 001 MgO acts as a template duringthe crystallization of CoFe. However, B in the finished magnetic tunneljunction construction undesirably reduces tunneling magnetoresistance(TMR) of the magnetic tunnel junction.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagrammatic sectional view of a substrate fragment inprocess in the fabrication of a magnetic tunnel junction in accordancewith an embodiment of the invention.

FIG. 2 is a view of the FIG. 1 substrate fragment at a processing stepsubsequent to that shown by FIG. 1.

FIG. 3 is a view of the FIG. 2 substrate fragment at a processing stepsubsequent to that shown by FIG. 2.

FIG. 4 is a view of the FIG. 3 substrate fragment at a processing stepsubsequent to that shown by FIG. 3, and in one embodiment is a view of amagnetic tunnel junction in accordance with an embodiment of theinvention independent of method of manufacture.

FIG. 5 is a view of the FIG. 4 substrate fragment at a processing stepsubsequent to that shown by FIG. 4.

DETAILED DESCRIPTION OF EXAMPLE EMBODIMENTS

Example methods of forming a magnetic tunnel junction in accordance withsome embodiments of the invention are initially described with referenceto FIGS. 1-5 with respect to a substrate fragment 10, and which maycomprise a semiconductor substrate. In the context of this document, theterm “semiconductor substrate” or “semiconductive substrate” is definedto mean any construction comprising semiconductive material, including,but not limited to, bulk semiconductive materials such as asemiconductive wafer (either alone or in assemblies comprising othermaterials thereon), and semiconductive material layers (either alone orin assemblies comprising other materials). The term “substrate” refersto any supporting structure, including, but not limited to, thesemiconductive substrates described above. Referring to FIG. 1,substrate fragment 10 comprises a base or substrate 11 showing variousmaterials having been formed as an elevational stack there-over.Materials may be aside, elevationally inward, or elevationally outwardof the FIG. 1-depicted materials. For example, other partially or whollyfabricated components of integrated circuitry may be provided somewhereabout or within fragment 10. Substrate 11 may comprise any one or moreof conductive (i.e., electrically herein), semiconductive, orinsulative/insulator (i.e., electrically herein) materials. Regardless,any of the materials, regions, and structures described herein may behomogenous or non-homogenous, and regardless may be continuous ordiscontinuous over any material which such overlie. Further, unlessotherwise stated, each material may be formed using any suitable oryet-to-be-developed technique, with atomic layer deposition, chemicalvapor deposition, physical vapor deposition, epitaxial growth, diffusiondoping, and ion implanting being examples.

First magnetic (i.e., ferrimagnetic or ferromagnetic herein) electrodematerial 12 (i.e., electrically conductive) is formed over substrate 11.In one embodiment, magnetic electrode material 12 comprises Co and Fe(e.g., an alloy comprising Co and Fe). In one embodiment, magneticelectrode material 12 is amorphous, and in one embodiment comprises B.Any suitable compositions may be used, with Co₄₀Fe₄₀B₂₀ being an examplethat includes B. Characterization of a material or region as being“amorphous” where used in this document requires at least 90% by volumeof the stated material or region to be amorphous. Further, reference to“magnetic” herein does not require a stated magnetic material or regionto be magnetic as initially formed, but does require some portion of thestated magnetic material or region to functionally be “magnetic” in afinished circuit construction of the magnetic tunnel junction. Firstelectrode material 12 may contain non-magnetic insulator,semiconductive, and/or conductive material or regions. However, firstmaterial 12 is characterized as being overall and collectively magneticand conductive even though it may have one or more regions therein thatare intrinsically locally non-magnetic and/or non-conductive. Firstelectrode material 12 may comprise, consist essentially of, or consistof Co, Fe, and B.

An example thickness for first electrode material 12 is about 10Angstroms to about 500 Angstroms. In this document, “thickness” byitself (no preceding directional adjective) is defined as the meanstraight-line distance through a given material or regionperpendicularly from a closest surface of an immediately adjacentmaterial of different composition or of an immediately adjacent region.Additionally, the various materials and regions described herein may beof substantially constant thickness or of variable thicknesses. If ofvariable thickness, thickness refers to average thickness unlessotherwise indicated. As used herein, “different composition” onlyrequires those portions of two stated materials that may be directlyagainst one another to be chemically and/or physically different, forexample if such materials are not homogenous. If the two statedmaterials or regions are not directly against one another, “differentcomposition” only requires that those portions of the two statedmaterials or regions that are closest to one another be chemicallyand/or physically different if such materials or regions are nothomogenous. In this document, a material, region, or structure is“directly against” another when there is at least some physical touchingcontact of the stated materials, regions, or structures relative oneanother. In contrast, “over”, “on”, and “against” not preceded by“directly” encompass “directly against” as well as construction whereintervening material(s), region(s), or structure(s) result(s) in nophysical touching contact of the stated materials, regions, orstructures relative one another.

Non-magnetic tunnel insulator 14 comprising MgO is formed over firstmaterial 12. Tunnel insulator 14 may comprise, consist essentially of,or consist of MgO. An example thickness is about 50 Angstroms to about200 Angstroms. In one embodiment, MgO of tunnel insulator material 14,Co, Fe, and B (of first material 12) are directly against one another.

Second magnetic electrode material 16 is formed over tunnel insulatormaterial 14. Any aspect(s) or attribute(s) described above for firstmaterial 12 may apply with respect to second material 16. In oneembodiment, at least one of first material 12 and second material 16comprises Co, Fe, and B. In one embodiment, a stack 20 is formed thatcomprises amorphous first magnetic electrode material 12, non-magnetictunnel insulator material 14 comprising MgO over first material 12, andamorphous second magnetic electrode material 16 over tunnel insulatormaterial 14, and wherein at least one of first material 12 and secondmaterial 16 comprises Co, Fe, and B. The elevational positions ofmaterials 12 and 16 may be reversed and/or an orientation other than anelevational stack may be used (e.g., lateral; diagonal; a combination ofone or more of elevational, horizontal, diagonal; etc.). In thisdocument, “elevational”, “upper”, “lower”, “top”, and “bottom” are withreference to the vertical direction. “Horizontal” refers to a generaldirection along a primary surface relative to which the substrate isprocessed during fabrication, and vertical is a direction generallyorthogonal thereto. Further, “vertical” and “horizontal” as used hereinare generally perpendicular directions relative one another andindependent of orientation of the substrate in three-dimensional space.

In one embodiment where each of materials 12 and 16 are amorphous, suchmaterials are crystallized into crystalline first magnetic electrodematerial 12 and crystalline second magnetic electrode material 16.Annealing substrate fragment 10 at about 350° C. in an inert atmosphereis an example technique for causing such crystallizing. Characterizationof a material or region as being “crystalline” where used in thisdocument requires at least 90% by volume of the stated material orregion to be crystalline. Tunnel insulator material 14 ideally is alsocrystalline either initially as-formed or becomes so while crystallizingan amorphous first magnetic electrode material 12 and/or an amorphoussecond magnetic electrode material 16. One of crystalline first material12 and crystalline second material 16 comprises magnetic referencematerial of the magnetic tunnel junction being formed. The other ofcrystalline first material 12 and crystalline second material 16comprises magnetic recording material of a magnetic tunnel junctionbeing formed.

Referring to FIG. 2, and in one embodiment, crystalline first material12, tunnel insulator material 14, and crystalline second material 16 arepatterned to form a magnetic tunnel junction structure or construction25 having opposing sidewalls 28 and 30 that individually comprisecrystalline first material 12, tunnel insulator material 14, andcrystalline second material 16. Any existing or yet-to-be developedpatterning technique(s) may be used. An example technique includesphotolithographic masking and etch (e.g., with or without pitchmultiplication). The above-described processing and patterning processesstack 20 to form opposing sidewalls 28 and 30 after the act ofcrystallizing materials 12, 14, and/or 16. Alternately, such or otherpatterning when used may be conducted to form sidewalls 28 and 30 beforethe act of crystallizing materials 12, 14, and/or 16.

Referring to FIG. 3, and in one embodiment, a B-absorbing material isformed over sidewalls 28, 30 of each of crystalline first electrodematerial 12, tunnel insulator material 14, and crystalline secondmagnetic electrode material 16. In one embodiment and as shown, all ofeach of sidewalls 28 and 30 is covered with B-absorbing material 40. Anexample technique of forming B-absorbing material is by a conformaldeposition of material 40 followed by anisotropic etch thereof tolargely remove material 40 from horizontal surfaces. In one embodiment,B-absorbing material 40 is formed to have a minimum lateral thickness ofabout 10 Angstroms to about 200 Angstroms, and in one embodiment aminimum lateral thickness of no more than about 100 Angstroms.

Referring to FIG. 4, B is absorbed from the at least one of crystallinefirst material 12 or crystalline second material 16 that comprises Co,Fe, and B laterally into B-absorbing material 40 that is over sidewall28 and over sidewall 30. A B-absorbing material is a material having acomposition that has an affinity for B, thus an affinity to absorb Bthere-into. The absorbing of B may occur predominantly (i.e., more than50% herein) during the forming of B-absorbing material 40 orpredominantly thereafter. Regardless, in one embodiment, B-absorbingmaterial 40 is annealed at a temperature of about 50° C. to about 450°C., for example which may facilitate the absorbing of B. Regardless, inone embodiment, at least some of the absorbed B chemically reacts withthe B-absorbing material to form a reaction product comprising B.Alternately or additionally, none or some of the absorbed B may not soreact.

In one embodiment, crystallization and B-absorption occurs aftersidewalls of the stack are formed (e.g., after patterning the stack). Insuch embodiment, the B-absorbing material is formed over the opposingsidewalls of each of the amorphous first magnetic electrode material,the tunnel insulator material, and the amorphous second magneticelectrode material prior to crystallizing the amorphous first and secondmagnetic electrode materials into crystalline first and second magneticelectrode materials, with the act of crystallizing also absorbing B fromthe at least one of the first and second materials comprising Co, Fe,and B laterally into the B-absorbing material that is over the opposingsidewalls.

In one embodiment, the B-absorbing material is conductive at least afterthe absorbing, and in one embodiment before and after the absorbing.Example conductive B-absorbing materials comprise elemental-form metalsor an alloy of two or more metal elements. Example metal elementscomprise Al, Ta, and W. Such may react with absorbed B to form one ormore conductive aluminum borides, tantalum borides, or tungsten borides,respectively.

In one embodiment, the B-absorbing material is semiconductive at leastafter the absorbing, and in one embodiment before and after theabsorbing. An example semiconductive B-absorbing material is AlN. By wayof example, absorbed B in such material may form material 40 to comprisea semiconductive mixture of aluminum nitride and aluminum boride.

In one embodiment, the B-absorbing material is insulative at least afterthe absorbing of B, and in one embodiment before and after the absorbingof B. Example insulative B-absorbing materials comprise Al₂O₃, acombination of SiO₂ and Al₂O₃, and a combination of Si₃N₄ and AlN (withsufficient Si₃N₄ in the composition to render it insulative as opposedto semiconductive due to presence of AlN).

In one embodiment, after absorbing the B, any remnant of the B-absorbingmaterial, any remnant of any reaction product of B with the B-absorbingmaterial, and the absorbed B are removed. This may be desirable, forexample, where the B-absorbing material is conductive or semiconductive(at least after the absorbing) to preclude electrode materials 12 and 16from being electrically shorted together in the finished circuitryconstruction. FIG. 5 by way of example shows such subsequent processingwhereby B-absorbing material 40 (not shown) from FIG. 4 has been removedfrom the substrate (e.g., by selective etching). In one embodiment, forexample where the B-absorbing material is insulative at least after theact of absorbing, the B-absorbing material, any remnant of any reactionproduct of B with the B-absorbing material, and the absorbed B areincorporated into a finished circuit construction encompassing themagnetic tunnel junction being formed.

In one embodiment, tunnel insulator 14 and magnetic electrode materials12 and/or 16 from which the B was absorbed are devoid of B after theabsorbing of B. In this document, “devoid of B” means 0 atomic % B to nomore than 0.1 atomic % B.

An embodiment of the invention encompasses a method used while forming amagnetic tunnel junction. Such a method includes forming non-magnetictunnel insulator material comprising MgO over magnetic electrodematerial (regardless of whether crystalline or amorphous) comprising Coand Fe (regardless of whether magnetic electrode material of more thanone magnetic electrode of a magnetic tunnel junction is formed). B isproximate (i.e., within 100 Angstroms herein) opposing facing surfacesof the tunnel insulator material and the magnetic electrode material(i.e., regardless of whether B is in the magnetic electrode material andregardless of whether MgO, Co, Fe, and B are directly against oneanother). For example and by way of example only, FIGS. 1 and 2 show Bbeing proximate opposing surfaces 50 and 70 of tunnel insulator material14 and magnetic electrode material 12, respectively, a result of B beingwithin or part of material 12. Alternately or additionally, by way ofexample, B may be within MgO regardless of whether B is within magneticelectrode material 12 and/or 16. Additionally, by way of example, someother B-containing material having minimum thickness no greater than 100Angstroms (not specifically shown or designated) may be between magneticelectrode material 12 or 16 and tunnel dielectric 14, with such Btherein thereby being proximate opposing facing surfaces of the tunnelinsulator material and the magnetic electrode material. Regardless,B-absorbing material is formed over a sidewall (e.g., one or both ofsidewalls 28, 30) of at least one of the magnetic electrode material andthe tunnel insulator material. B that is proximate opposing surfaces 50,70 is absorbed laterally into the B-absorbing material. Any otherattribute(s) or aspect(s) as described above and/or shown in the Figuresmay be used.

Embodiments of the invention encompass a magnetic tunnel junction (i.e.,a structure) independent of method of manufacture. Such a magnetictunnel junction comprises a conductive first magnetic electrodecomprising magnetic recording material and a conductive second magneticelectrode spaced from the first electrode and comprising magneticreference material. A non-magnetic tunnel insulator material is betweenthe first and second electrodes. At least one of the magnetic recordingmaterial and the magnetic reference material comprises Co and Fe. Thetunnel insulator material comprises MgO. The first magnetic electrode,the second magnetic electrode, and the tunnel insulator materialcomprise a stack having opposing sidewalls. Insulative material islaterally proximate, in one embodiment directly against, the opposingstack sidewalls. The insulative material comprises B, at least one of Siand Al, and at least one of N and O.

In one embodiment, the insulative material comprises Al and in oneembodiment comprises N. In one embodiment, the insulative materialcomprises Al and N. In one embodiment, the insulative material comprisesO and in one embodiment comprises Al and O. In one embodiment, B ispresent in the insulative material at a concentration of at least about10 atomic percent and in one embodiment at least about 20 atomicpercent. Any other attribute(s) or aspect(s) as described above and/orshown in the Figures may be used in magnetic tunnel junction deviceembodiments.

The example embodiments of FIGS. 1-5 depict single magnetic tunneljunctions (SMTJs). However, dual magnetic tunnel junctions (DMTJs) ormore than dual (two) magnetic tunnel junctions are contemplated.

CONCLUSION

In some embodiments, a method used while forming a magnetic tunneljunction comprises forming non-magnetic tunnel insulator material overmagnetic electrode material. The tunnel insulator material comprises MgOand the magnetic electrode material comprises Co and Fe. B is proximateopposing facing surfaces of the tunnel insulator material and themagnetic electrode material. B-absorbing material is formed over asidewall of at least one of the magnetic electrode material and thetunnel insulator material. B is absorbed from proximate the opposingfacing surfaces laterally into the B-absorbing material.

In some embodiments, a method of forming a magnetic tunnel junctioncomprises forming a stack comprising amorphous first magnetic electrodematerial, non-magnetic tunnel insulator material comprising MgO over thefirst material, and amorphous second magnetic electrode material overthe tunnel insulator material. At least one of the first and secondmaterials comprises Co, Fe, and B. The amorphous first and secondmagnetic electrode materials are crystallized into crystalline first andsecond magnetic electrode materials. One of the crystalline firstmaterial and the crystalline second material comprises magneticreference material of the magnetic tunnel junction being formed. Theother of the crystalline first material and the crystalline secondmaterial comprises magnetic recording material of the magnetic tunneljunction being formed. After the crystallizing, B-absorbing material isformed over opposing sidewalls of each of the crystalline first magneticelectrode material, the tunnel insulator material, and the secondmagnetic electrode material. B is absorbed from said at least one of thecrystalline first and second materials comprising Co, Fe, and Blaterally into the B-absorbing material that is over said opposingsidewalls.

In some embodiments, a method of forming a magnetic tunnel junctioncomprises forming amorphous first magnetic electrode material over asubstrate. The first material comprises Co, Fe, and B. Non-magnetictunnel insulator material comprising MgO is formed over the firstmaterial. Amorphous second magnetic electrode material is formed overthe tunnel insulator material, and comprises Co, Fe, and B. Afterforming the amorphous first and second magnetic electrode materials andthe tunnel insulator material over the substrate, the amorphous firstand second magnetic electrode materials are crystallized intocrystalline first and second magnetic electrode materials. After thecrystallizing, the crystalline first material, the tunnel insulatormaterial, and the crystalline second material are patterned to form amagnetic tunnel junction structure having opposing sidewalls thatindividually comprise the crystalline first material, the tunnelinsulator material, and the crystalline second material. One of thecrystalline first material and the crystalline second material comprisesmagnetic reference material of the magnetic tunnel junction beingformed. The other of the crystalline first material and the crystallinesecond material comprises magnetic recording material of the magnetictunnel junction being formed. All of said opposing sidewalls are coveredwith B-absorbing material. B is absorbed from the first and secondmaterials laterally into the B-absorbing material that covers all ofsaid opposing sidewalls. At least some of the absorbed B is reacted withthe B-absorbing material to form a reaction product comprising B.

In some embodiments, a magnetic tunnel junction comprises a conductivefirst magnetic electrode comprising magnetic recording material and aconductive second magnetic electrode spaced from the first electrode andcomprising magnetic reference material. A non-magnetic tunnel insulatormaterial is between the first and second electrodes. At least one of themagnetic recording material and the magnetic reference materialcomprises Co and Fe. The tunnel insulator material comprises MgO. Thefirst magnetic electrode, the second magnetic electrode, and the tunnelinsulator material comprise a stack having opposing sidewalls.Insulative material is laterally proximate the opposing stack sidewalls.Such insulative material comprises B, at least one of Si and Al, and atleast one of N and O.

In some embodiments, a method of forming a magnetic tunnel junctioncomprises forming a stack comprising amorphous first magnetic electrodematerial, non-magnetic tunnel insulator material comprising MgO over thefirst material, and amorphous second magnetic electrode material overthe tunnel insulator material. At least one of the first and secondmaterials comprises Co, Fe, and B. B-absorbing material is formed overopposing sidewalls of each of the amorphous first magnetic electrodematerial, the tunnel insulator material, and the amorphous secondmagnetic electrode material. The amorphous first and second magneticelectrode materials are crystallized into crystalline first and secondmagnetic electrode materials. One of the crystalline first material andthe crystalline second material comprises magnetic reference material ofthe magnetic tunnel junction being formed. The other of the crystallinefirst material and the crystalline second material comprises magneticrecording material of the magnetic tunnel junction being formed. The actof crystallizing also absorbs B from said at least one of the first andsecond materials comprising Co, Fe, and B laterally into the B-absorbingmaterial that is over said opposing sidewalls.

In compliance with the statute, the subject matter disclosed herein hasbeen described in language more or less specific as to structural andmethodical features. It is to be understood, however, that the claimsare not limited to the specific features shown and described, since themeans herein disclosed comprise example embodiments. The claims are thusto be afforded full scope as literally worded, and to be appropriatelyinterpreted in accordance with the doctrine of equivalents.

The invention claimed is:
 1. A magnetic tunnel junction, comprising: aconductive first magnetic electrode comprising magnetic recordingmaterial; a conductive second magnetic electrode spaced from the firstelectrode and comprising magnetic reference material; a non-magnetictunnel insulator material between the first and second electrodes; atleast one of the magnetic recording material and the magnetic referencematerial comprising Co and Fe; the tunnel insulator material comprisingMgO; the first magnetic electrode, the second magnetic electrode, andthe tunnel insulator material comprising a stack having opposingsidewalls; and insulative material laterally proximate the opposingstack sidewalls, the insulative material comprising each of B, Al, andN.
 2. The magnetic tunnel junction of claim 1 wherein the insulativematerial comprises Si.
 3. The magnetic tunnel junction of claim 1wherein B is present in the insulative material at a concentration of atleast about 10 atomic percent.
 4. The magnetic tunnel junction of claim1 wherein B is present in the insulative material at a concentration ofat least about 20 atomic percent.
 5. The magnetic tunnel junction ofclaim 1 wherein the each of the B, Al, and N is directly against theopposing stack sidewalls of the conductive first magnetic electrode, theconductive second magnetic electrode, and the non-magnetic tunnelinsulator material.
 6. A magnetic tunnel junction, comprising: aconductive first magnetic electrode comprising magnetic recordingmaterial; a conductive second magnetic electrode spaced from the firstelectrode and comprising magnetic reference material; a non-magnetictunnel insulator material between the first and second electrodes; atleast one of the magnetic recording material and the magnetic referencematerial comprising Co and Fe; the tunnel insulator material comprisingMgO; the first magnetic electrode, the second magnetic electrode, andthe tunnel insulator material comprising a stack having opposingsidewalls; and insulative material laterally proximate the opposingstack sidewalls, the insulative material comprising each of B, Si, andN.
 7. The magnetic tunnel junction of claim 6 wherein the each of the B,Si, and N is directly against the opposing stack sidewalls of theconductive first magnetic electrode, the conductive second magneticelectrode, and the non-magnetic tunnel insulator material.
 8. A magnetictunnel junction, comprising: a conductive first magnetic electrodecomprising magnetic recording material; a conductive second magneticelectrode spaced from the first electrode and comprising magneticreference material; a non-magnetic tunnel insulator material between thefirst and second electrodes; at least one of the magnetic recordingmaterial and the magnetic reference material comprising Co and Fe; thetunnel insulator material comprising MgO; the first magnetic electrode,the second magnetic electrode, and the tunnel insulator materialcomprising a stack having opposing sidewalls; and insulative materiallaterally proximate the opposing stack sidewalls, the insulativematerial comprising each of B, Si, and O.
 9. The magnetic tunneljunction of claim 8 wherein the each of the B, Si, and O is directlyagainst the opposing stack sidewalls of the conductive first magneticelectrode, the conductive second magnetic electrode, and thenon-magnetic tunnel insulator material.
 10. A magnetic tunnel junction,comprising: a conductive first magnetic electrode comprising magneticrecording material; a conductive second magnetic electrode spaced fromthe first electrode and comprising magnetic reference material; anon-magnetic tunnel insulator material between the first and secondelectrodes; at least one of the magnetic recording material and themagnetic reference material comprising Co and Fe; the tunnel insulatormaterial comprising MgO; the first magnetic electrode, the secondmagnetic electrode, and the tunnel insulator material comprising a stackhaving opposing sidewalls; and insulative material laterally proximatethe opposing stack sidewalls, the insulative material comprising each ofB, SiO₂, and Al₂O₃.
 11. The magnetic tunnel junction of claim 10 whereinthe each of the B, SiO₂, and Al₂O₃ is directly against the opposingstack sidewalls of the conductive first magnetic electrode, theconductive second magnetic electrode, and the non-magnetic tunnelinsulator material.
 12. A magnetic tunnel junction, comprising: aconductive first magnetic electrode comprising magnetic recordingmaterial; a conductive second magnetic electrode spaced from the firstelectrode and comprising magnetic reference material; a non-magnetictunnel insulator material between the first and second electrodes; atleast one of the magnetic recording material and the magnetic referencematerial comprising Co and Fe; the tunnel insulator material comprisingMgO; the first magnetic electrode, the second magnetic electrode, andthe tunnel insulator material comprising a stack having opposingsidewalls; and insulative material directly against the opposing stacksidewalls, the insulative material comprising a combination of insulatormaterial and semiconductive material, the insulative material havingsufficient insulator material to render the insulative materialinsulative as opposed to semiconductive.
 13. The magnetic tunneljunction of claim 12 wherein the insulator material comprises Si₃N₄. 14.The magnetic tunnel junction of claim 12 wherein the semiconductivematerial comprises AlN.
 15. The magnetic tunnel junction of claim 14wherein the insulator material comprises Si₃N₄.